Luminescence property, energy transfer and thermal property of color tunable phosphor Ca9-wCe0.5Y0.5-x-y-z(PO4)7:xTb3+, yEu3+, zSm3+, wMn2+

Series of Ca 9- w Ce 0.5 Y 0.5- x - y - z (PO 4 ) 7 : x Tb 3+ , y Eu 3+ , z Sm 3+ , w Mn 2+ phosphors are synthesized by a high temperature solid state method. The spectral property and fluorescence decay curves are measured and used to demonstrate the energy transfer effect in Ce 3+ -Tb 3+ , Ce 3+ -Sm 3+ , Ce 3+ -Eu 3+ , Tb 3+ -Sm 3+ , Tb 3+ -Eu 3+ and Tb 3+ -Mn 2+ . For Ca 9 Ce 0.5 Y 0.5 (PO 4 ) 7 , the concentration of Ce 3+ is higher and it can act as activator and sensitizer simultaneously. Ce 3+ and Tb 3+ can emit blue and green light under near ultraviolet excitation, respectively. Sm 3+ , Eu 3+ and Mn 2+ can produce red emission. In order to generate white light, Ce 3+ /Tb 3+ /Sm 3+ , Ce 3+ /Tb 3+ /Eu 3+ and Ce 3+ /Tb 3+ /Mn 2+ doped phosphors are investigated, and Ca 8.8 Ce 0.5 Y 0.33 (PO 4 ) 7 :0.17Tb 3+ ,0.20Mn 2+ can create high quality white light. Its color rendering index can be high up to 80.2 and correlated color temperature is 4735 K, and its thermal stability is high. The result indicates that the acquired phosphors can be potential for the use of ultraviolet excited white light emitting diodes .